diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp
--- a/llvm/lib/IR/Attributes.cpp
+++ b/llvm/lib/IR/Attributes.cpp
@@ -597,6 +597,8 @@
 }
 
 bool AttributeImpl::operator<(const AttributeImpl &AI) const {
+  if (this == &AI)
+    return false;
   // This sorts the attributes with Attribute::AttrKinds coming first (sorted
   // relative to their enum value) and then strings.
   if (isEnumAttribute()) {